prevalence of HTML mail

Is HTML mail finally sufficiently ubiquitous that one can simply assume that anyone you send it to will have the ability to read it?

I'm looking for statistics on popularity of mail readers, and having a hard time finding any. Do any of you know of any?

My random wild-assed guess would be something like:

  • 40% Outlook
  • 30% AOL
  • 25% Yahoo/Hotmail/etc
  • 4% Eudora/Netscape
  • 1% everything else
...but surely someone has actually studied this?

Eudora has shitty HTML support (it displays basic tags, but not tables). However, I think all the others on that list display HTML properly. (If my guesses are right, that's 95%.)

(Please note! This is not an invitation for you to tell me that you use /bin/mail in an 80x24 terminal emulator. I'm looking for numbers, not a survey of the personal preferences of power-nerds.)

    Update, Jan 4: The most believable numbers I've seen are these, at; they are approximately in line with my guesses. I think it's safe to assume that Damned Near Everybody is capable of receiving and properly displaying HTML email (though of course they may not prefer it.) Thanks to zonereyrie for pointing to that survey.
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76 Responses:

  1. msjen says:

    don't forget the OSX mail program -- which you could probably file under eudora. it seems to do fine with html, but then again, what do i know.

    • jwz says:

      Yeah, I was assuming that most people who upgraded to OSX would have continued using their previous mail reader, and not switched to yet. But, Google Zeitgeist puts MacOS at 3% anyway, and I suspect more than half of the Mac users in the world are still running OS9.

      • gordonzola says:

        I suspect more than half of the Mac users in the world are still running OS9.

        I am, but I'm upgrading any day now, I swear.

      • cow says:

        Almost everyone I know who uses OS X has switched to But then again, I still use PINE, so it's quite possible that I know a skewed sample.

    • jeremiahblatz says: presumably is among the 1%: everything else. It has excellent HTML support (kHTML).

  2. prasun says:

    people in some univs/companies use their own clients which might or might not support. But I guess they would be included in the 1%.

  3. icis_machine says:

    i guess i'm still a tad taken back that people want their email in html form since virii seem to take advantage of the html-ness.

  4. macguyver says:

    For mailings to several lists, I use multipart, plain text and html, and I've never had a complaint.

    • magicpacket says:

      What lists do you mail to? I'll go complain :-P

      • macguyver says:

        Double-opt-in lists for musicians, artists, venues. I wasn't aware that people hated being on mailing lists. After all, newsgroups aren't for everyone.

  5. lovingboth says:

    It will depend on who you're talking about. Home and SME users are - in general - going to use whatever came with the PC or ISP. So those figures are probably (sadly) roughly the right size.

    Corporate users are - ditto - going to use whatever their IT people tell them. Which will be Outlook or Notes or... but not Hotmail or AOL etc.

    And academic / geek etc users will use something better.

    The answer to your opening question is 'no'.

    • jwz says:

      The answer to your opening question is 'no'.

      And on what do you base that? If the only people unable to read HTML are those people who are willfully avoiding technology that is easily available to them (e.g., college students who think Pine is 'l33t) then I quite frankly don't think they count.

      • romulusnr says:

        well, pine can technically read html, via spawning lynx as a viewer.

        the day someone sends me an actually important or valuable email in html is the day i'll consider turning off that procmail recipe that deletes 'text/html' mail with only one attachment.

        • livejournalsux says:

          the day someone sends me an actually important or valuable email in html is the day i'll consider turning off that procmail recipe that deletes 'text/html' mail with only one attachment.
          Not that you'd know, since you delete it geekomatically.

      • lovingboth says:

        Ok, then the expanded answer is 'yes, but do you want to appear to be a prat?'

        If you must do it, then don't have images (or, if you must, embed them in the email rather than just including the link...)

        For me, the most interesting section of the clickz article is this one:

        Q. Do you prefer receiving HTML or text email?

        HTML 41.95%
        Text 31.52%
        No pref 26.53%

        The biggest email list I'm responsible for has 9k or so subscribers. The HTML/text split there is 60/40 - on a list system where the former is the default.

        Doubtless most of the 40% could receive HTML, but they don't want it.

        • nzchrisb says:

          If you must do it, then don't have images (or, if you must, embed them in the email rather than just including the link...)

          Bugger that if you must do it us a link so I don't end up with a mail box full of jpegs.

          • watchingsitcoms says:

            The problem with linking images is that it's a tool used by spammers to see when you read your mail.

            • kchrist says:

              True, but the problem with attaching a bunch of .jpgs is that I have to wait to download them all.

              • wfaulk says:

                Whereas you don't have to wait if they're on web sites instead?

                • kchrist says:

                  e-mail != the web. If I'm browing the web I expect images; if I'm checking my e-mail I don't. See previous post re: mailbox full of unexpected .jpgs.

                  • jwz says:

                    You guys are so insightful! For example, even though I didn't ask that question, all of you realized that the thing I was really hoping to start a discussion about here was HTML email: Threat, or Menace? It's amazing how you can just read between the lines like that.

                  • nzchrisb says:


    • harryh says:

      And academic / geek etc users will use something better.

      The answer to your opening question is 'no'.

      I think you vastly overestimate the number of academic/geek users if you think the first implies the second.

      I also question your definition of better if you think that using an e-mail client that doesn't display HTML is somehow better.

      I too used to think that e-mail should be send in plain text with 80 character line lenghts. The way god intended you know? Eventually though I grew a brain and abandoned my religion.

      • lovingboth says:

        I say it for the same reason that I think people who come up with websites that can't be viewed with a Mac, or with a non-IE browswer are stupid.

        And it also depends on whether or not you're using images in your HTML mail...

      • lovingboth says:

        And before I forget, better <> can't read HTML mail.

        Better = better than Outlook [Express] or Notes or AOL or a web service.

  6. vi_z says:

    There's also Opera mail and its use is growing, as they make it better. Do not know whether they've considerably overgrown 1 percent, though (I use it at home!).

  7. insom says:

    My experience in companies that I deal with is:

    80% - Outlook (Express)

    19.9% - Lotus Notes, including rabidly out of date versions.

    Everything else (even PINE can grok some HTML, and you can open the text/html part in your browser).

    Why are you looking for these stats? Most *good* automated-responses/newsletters off either a text option or use multipart.

  8. cadmus says:

    Outlook or Outlook Express? Completely different codebase though both use mshtml.dll (Trident, the rendering engine for Internet Explorer) to display HTML e-mail.

  9. wafonso says:

    From a random sample of 1000 messages in a large mail spool (collected from several mailboxes), 590 of them had either a "X-Mailer" or a "User-Agent" header. Of these, 72.2% were either Outlook or Outlook Express. The second place goes to Eudora and something the identifies itself only as "3.1.76-XP/NG", with 3.2% each, followed closely by Mozilla with 2.7% and AOL with 2%. Everything else was under 1.5%. However, a larger sample could possibly give better results (but processing the strings to remove things like version info is a drag).

    • damned_colonial says:

      Outlook / Outlook Express: 31%
      Mutt: 20%
      Mozilla: 16%
      Eudora: 9%
      Internet Mail Service (what's this?): 7%

      Web clients (IMP, Squirrelmail, etc): 6%
      Graphical Linux clients (KMail, Evolution): 3%
      Other command line Unix clients (not mutt): 2%
      Corporate clients (Lotus, Novell, etc) : 2%

      Unknown or just generally marginal: 5%

      Sample size: 470 emails with User-Agent/X-Mailer headers, from a mailbox of 719 emails

      Of course, my own email is a skewed sample. I could run the figures over the mailboxes at work, I suppose, but it's still a Linux company so that would still be skewed. Perhaps if I ran the figures over my large collection of emails from non-technical mailing lists? Hrm.

  10. zonereyrie says:

    How many of those HTML capable clients allow users to turn off the HTML? Not that I've spent a lot of time researching it, but I couldn't find a way to tell Outlook (standard at work) to force presentation as plain text. I do, however, generally convert all email to plain text only when I reply - breaking the HTML chain. And I set it to only send new email as plain text. Though I've received some flak about not 'color coding' my replies. Ugh....

    Even terminal clients like mutt (what I use for my personal email) can handle HTML with a helper, I have mine configured to use links, which works rather well. But I only did that because of a few companies I deal with that insist on sending HTML formatted email and don't do multipart. I've whitelisted a handful of HTML senders, but everyone else runs into my procmail 'text/html' MIME filter that sends back an auto-reply telling them that if they want to reach me they'll need to send plain text.

    • jwz says:

      Here's me dying of non-shock that saying

      (Please note! This is not an invitation for you to tell me that you use /bin/mail in an 80x24 terminal emulator. I'm looking for numbers, not a survey of the personal preferences of power-nerds.)

      didn't do any good.

      I think it's swell that you whitelist your friends, I really do.

      • zonereyrie says:

        Well, I tossed that on as an afterthought - the main thing was that I really do wonder how many of the HTML capable clients have some kind of controls? Can it be presumed that stats that show 50% Outlook use mean 50% HTML acceptance? It seems like for Outlook that is the case, there doesn't seem to be any want to make it not accept HTML (3rd party tools excepted).

        The secondary point was that even if someone is using a terminal client, they probably at least have the ability to accept HTML if they want it. I don't know about /bin/mail off-hand, but elm and mutt both grok text/html enough to call a helper like lynx or links.

        HTML seems to be pervasive at this point with the majority of clients at least capable of handling it. Aside from obstinate folks like myself, I would say it is indeed safe to presume that any given random user can handle HTML email these days.

        • jwz says:

          The vast, vast majority of people never change the defaults.

          Besides that, even if a mail program had a switch that let you say "convert HTML to plain-text before showing it to me" (and I can't imagine that feature existing except in a tty program) it would also be possible to turn that switch off when you need to.

          Like I said in another reply, I don't think that people who intentionally shun technology that they have easy access to count. Nobody sane (nobody but a Linux weenie) would inflict that kind of lossage on themselves.

          • zonereyrie says:

            The main reason I default to blocking text/html is simple - spam. Very, very little of the email I've asked to receive comes as text/html, most is text/plain and some is multipart. But a *lot* of the spam I receive comes as text/html. Just blocking that immediately slashed the amount of spam I received.

            At work, where I can't block it by default - can't really block anything by default - pure HTML emails account for a lot of the spam that lands in my inbox.

            Then there is the same damage you get with websites - people setting textured backgrounds and low contrast font colors or fancy font faces, embedding images into their signatures that are orders of magnitude larger than the rest of the message.

            I don't blame the technology though, it isn't HTML's fault that people send emails for "Where do you want to go to lunch today?" with more markup than content and a few animated gifs thrown in just because.

            It would be nice to be able to see everything in plain text by default - as you say, if there is something of *content* in the HTML, then you can always toggle it. It is easier and faster to read most messages in plaintext without all the decoration - and Outlook certainly renders text faster than it does HTML.

          • mapzter says:

            Mozilla has that feature. I like it. I can't recall the last html mail I received, that wasn't just as readable formatted as plain text (well, except for all the spam). But yeah, if I needed to, I would switch HTML back on.

            • cetan says:

              And, of course, it follows that Thunderbird has this feature.

              It's quite nice.

          • transiit says:

            I don't think that people who intentionally shun technology that they have easy access to count. Nobody sane (nobody but a Linux weenie) would inflict that kind of lossage on themselves.

            I'm confused. I read over here about how you use(d) netscape 3, with an eye towards avoiding things devoid of content (with an emphasis on reliance of layers, javascript, plugins, etc)

            All of that crap is easy access technology that I gladly shun, even with (and more to the point, because of) the information loss.

            Are you suggesting that HTML mail is such a pivotal technology leap that anyone who avoids it could only possibly be a zealot?

            I believe I would disagree with that sentiment.


            • jwz says:

              Is your web site written in text/plain?

              Neither is mine.

              • transiit says:

                sorry - I didn't realize the importance of looking at my website using my mail reader.

                do you talk to your webserver over port 25?

                or is this supposed to be the future of the intarweb, forwarding entire websites around over smtp?

          • 21cdb says:

            Mailsmith on OS X does this. it makes a kind of half-ass rendering of the HTML in plain text. You can launch a browser if you want to see it in HTML.

          • damned_colonial says:

            My main reason for using a not-very-HTML-capable mail client is that I have a very strong preference for using the same powerful editor that I use for my work, for email. If someone can show me how to attach that editor to Mozilla (for instance) I would be quite prepared to consider switching to a more graphically oriented client.

            That might make me an editor-zealot, but it doesn't make me an anti-HTML zealot.


            who is sure this isn't the only LJ comment she's ended with...

    • wire_on_fire says:

      Apparently Outlook 2003 lets you force the use of text, but previous versions don't. Supposedly, it's quite cool.

      After they fixed the mime parsing bugs, I've been using the "AutoPreview" option from the View menu. If there's a textual equivelent, it'll display it.

      The thing that's obnoxious for me is mail client authors who don't automatically have the program create a plain-text version of an HTML message, which means that I might accidentally decide that something's a spam come-on when it's a real message. I really don't want to attract more spam by viewing spam messages, although my research seems to indicate that the spammers haven't been using as many web-bugs in HTML email as they used to -- but I may be wrong there. And, unfortunately, I haven't found a way to make IE not open images while in the "Secure" zone.

      *sigh* and I used to -like- email.

    • skington says:

      Mac OS X Mail has a menu option to view the plain-text equivalent of a given message. It also has an option to not display images or any other objects if you don't want to (if you decide the message isn't spam, you can click a button to download them manually). It also has very good spam-filtering, and, of course, nobody is writing viruses for the Mac that spread via email, so that one's covered as well.

      Most excellently, it uses the older (but perfectly acceptable) rich text format when sending styled messages, which does all that you want from HTML without having all of the bloat.

      • kchrist says:

        Mac OS X Mail has a menu option to view the plain-text equivalent of a given message.

        Barely. You can toggle HTML mail to plain text when you're reading it, but there's no way to make that the default. Even closing and reopening the message you toggled resets it back to HTML.

        If I'm missing something here I'd love to know. I just actually sent Apple feedback about forcing HTML in Mail to display as text.

        </text/plain weenie (who doesn't miss the irony of using a pseudo-HTML tag to say that)>

  11. fo0bar says:

    I used to work at a marketing company that, among other things, did pseudo-spam newsletters to clients' pre-existing customers.

    Your wild guesses are pretty accurate, at least from the numbers I remember from 3 years ago. I used to do compatibility tests of various levels of HTML whiz-bangedness. This is what I recall from those days:

    * Up until like AOL 8 (or 7, whatever was the latest version 3 years ago), the HTML support was CRAP. You're basically limited to bold, italic, underline, and font colors/sizes. Now, the latest version of the client wasn't too bad, and the webmail client was pretty good, but still, a lot of people were using old-ass AOL clients. Fortunately, AOL users are easy to identify (what with that and everything), so there were 3 templates: text, html, and aol (very basic html, no multipart/alternative block).
    * Yahoo's webmail client would only display HTML if the text/html part was the first part of the multipart/alternative block. Some no-name webmail client would only work if text/html was the LAST part of multipart/alternative. Guess which layout we went with.
    * Yeah, Eudora has crappy HTML support. This is us caring...
    * Despite its reputation, outlook actually worked very well with regard to HTML display. It would handle nearly anything you threw at it.
    * On a sidenote, nearly all of the webmail clients' mime-handling capabilities are SHIT, which led me to release kmMail upon the world. (I swear, one of these days I'll release an updated version.)

  12. rxrfrx says:

    My university and the universities of almost all of my friends use IMP Webmail. Although we're encouraged to use Pine or Outlook or OS X Mail, everybody tends to use IMP when they're on a friend's computer, at the library, etc. IMP, or at least the implementation used by my university, has no HTML support. URL's are automagically converted to links.

  13. zonereyrie says:

    This may be what you're looking for - June 2002 though:

    Not surprisingly email marketers seem very interested in which clients are being used - more stats:

    Of course, these are self-selecting data sets.

    And here - - they refer to client statistics collected from Jupiter Research, so that may be another place to look.

    • jwz says:

      Cool. The "clickz" one sounds sensible, though their sample size is fairly small and biased.

      The "emaillabs" one has a pie-chart on that page demonstrating that AOL and Netscape Communicator are tied at 3% each -- so I think it's safe to assume that their numbers are complete nonsense (even for 2002.)

  14. blackirisdancer says:

    Here's a survey on a rather terrifying “web marketing” site. They took two sets of data, one representing business use, one representing casual use (they interviewed a Bible study group of all things for the latter set). Their conclusions more are less in line with yours (AOL did worse, the various sundry webmail services and “everything else” did rather better), thus proving that the scientific method is unnecessary.

  15. grimmtooth says:

    I don't know how many of the Linux clients support HTML email, but that's one thing to consider.

    Also, some mail services have actually started blocking HTML email, not intentionally, but because it sometimes contains signatures that make it look suspicious. For example, HTML mail from livejournal through my POP server at is almost 100% blocked -- I never see it.

    So, it's more than just a client thang. Every link in the chain could have some effect.

    • deviant_ says:

      Pretty much all of the mail clients that people actually use on Linux support html mail at this point -- either internally, or as pine does with /usr/bin/htmlview .

      At the same time, I haven't seen any recent data which suggests that Linux users even make up a statistically significant chunk of email users at this point in time. After all, Linux is a mere 1% on the google zeitgeist, and I have to assume that google users and email users corelate relatively closely.

      I do have data to support the statement above regarding which mail clients people actually use (or, rather, which ones they install), but only for one fairly popular distro. But I don't think I can make the raw numbers available, due to our terms when collecting the data.

  16. suppafly says:

    i've never seen an html email that eudora couldn't display properly.. you just have to make sure you tell it to use IE internally for html emails instead of whatever its own thing is.

  17. giles says:

    I use a hybrid system that relays my mail through a series of electrodes hooked up to a tiny Scottish man with semaphore flags.

    His HTML support is absolute shite. It's hella l33t though.

  18. livejournalsux says:

    Why do you want to know? Just curious.

  19. westyx says:

    Use calypso (your 1%). It might grok html, but i turned that off. turns urls into clickable links, tho, if that's what you need.

  20. tangaroa says:

    To the tune of:
    Abney Park - Kine

    Look at all of the e-mails
    Move down, move up
    I'm gonna check my email
    Log on, bring it up

    This is where I e-mail myself
    and I show that I'm not blind
    I haven't learned Mutt yet so
    I'm still using Pine

    Still a console geek
    and Elm just stinks
    Still a console geek
    and Elm just stinks

    No fear the Lovesan worm
    No gifs, no pr0n
    No fear the Lovesan worm
    No gifs, no pr0n
    [repeat etc]

    Can't help you with numbers, but given the aghast gaping-mawed reaction of mailing list users whose worldview has just been destroyed by telling them that there are people who can't read HTML mail, I'd presume that there are very few still in that position. That those few of us are loudmouthed jackasses who will never stop complaining at you is probably reason enough to send in text unless you want to do something special.

    Of course, if somebody really truly wants to read the email but their client doesn't support HTML, they can save the message to a file and open it in a browser.

  21. belgand says:

    I would probably include Pegasus in the Eudora/Netscape category as well.

    Likewise while I use Eudora and it indeed has very shitty HTML (it tries to read links from text and thus screws up if someone actually puts it down using tags) it also lacks the ability to turn it off. I've thought about switching to Thunderbird, but I don't care for how it handles the actual display of messages and don't like preview windows. Likewise the newsreader isn't to my liking compared to Agent. I'm not certain whether it allows the removal of HTML either.

    There are some pretty good reasons to turn off HTML e-mail. For one the majority of what's being sent relies on the transmission of text and text alone and it's not likely to change anytime soon. Likewise HTML e-mail is not very well implemented at the present as you mention and thus is more likely to come out looking shitty regardless of whether you're one of the select few that use it appropriately. It also simply bloats the download and not for any useful reason, but so I can get e-mail that someone sends in magenta text on a purple background in some excessive font. The green on black layout here is readable and looks good, but sadly most people (as shown by AIM/ICQ and such) do not have that same ability and feel that they must blind the user to express themself. Though very dark blue that looks almost black, but not quite black enough is highly irritating.

    The questions thus isn't so much will people be able to read it, but do they want to? I doubt it will ever come to pass that it is a useful and valuable feature.

    Anyhow, I'm shocked that that many people use AOL or webmail. The Outlook I can see though. Damn, I remember not that long ago when almost everyone used Eudora on Windows. The switch to Outlook seemingly came overnight.

  22. lightinchains says:

    For both UseNet and mail. I love it - but it doesn't do HTML. I don't consider it a loss. At work, I use Outlook, but I send as plain text and I get virtually no HTML e-mails.

  23. confuseme says:

    Despite the fact that your post is about feature availability and mail reader popularity, and despite your specific plea not to be inundated with messages about personal preferences, I would like to tell you that I use [insert crippled, minority MUA here].

    [Insert useless information about minority MUA's HTML abilities here].

    It being my personal preference, I find that I like it pretty well, even though [insert breathtaking lossage here]. Your insinuation that I am part of an insignificant minority [choose one: offends me; brings me great joy; has not yet occurred to me]!

    • ciphergoth says:

      I want to have your babies.

    • kcm says:

      Your insinuation that I am part of an insignificant minority [choose one: offends me; brings me great joy; has not yet occurred to me]!

      I was thinking more "(outwardly) offends me (which) brings me great joy (inside) (because boy do I love the attention from being obstinate)". maybe I'm bitterly amused.

  24. secularkangaroo says:

    I use Eudora and it does HTML pretty well. I like text-only better, though.

    • cje says:

      I also use Eudora, but I've got it set to "text only" because most HTML emails just bug me.


  25. ivorjawa says:

    I've installed filters in MUTT to deal with HTML, I get so much HTML mail from legitimate sources that it's the only way to deal with my email.

  26. transgress says:

    if i had to make a guess, id say most of the world uses outlook followed by web based emails. It seems html formatted mail is more or less the norm now, but perhaps thats because management likes to send html mail so that we can see their signature at 36px in 4 different colors and everyone more or less just had to accept it, because after all, its your boss.

    i still strip html from my emails though

  27. rambletron3000 says:

    On university campuses there's still a good number of people who use telnet/pine to access their mail, so if that's part of your demographic of mail recepients, it can be a concern.

    I personally prefer plain-text mail because it's smaller, doesn't fuck up/take up tons of room when you're having a back and forth quoted conversation with someone, and simply I have to desire to use it, except for maybe the occasional italic.

    Oh, and for the record, everyone I know that doesn't just use webmail uses Mozilla Mail/Thunderbird. And the webmail people are always hitting their storage limits and bouncing my messages because people have filled it up with HTML nonsense. :)

  28. legolas says:

    Strange you have thrown eudora and netscape together? Netscape/mozilla, yes but eudora/netscape?

    • jwz says:

      Netscape/Mozilla are the same thing. I grouped it with Eudora because I think they are likely the 4th/5th most popular choice, but they're both so far down in the noise that they're almost ignorable, so who cares which of them is more popular.

  29. aitp says:

    Eudora has shitty HTML support (it displays basic tags, but not tables).

    Modern (5.0+) Eudora will use Microsoft's viewer if you ask it nicely (and, in fact, that's the default configuration). With the Microsoft viewer, anything Outlook can render, Eudora can, too.

    <defense of="l33t-ness">Of course, I have that option turned off; I don't use no stinking &micro$ft_or_equivalent_mispelling; shite.</defense>


  30. omnifarious says:

    It's what I most commonly use, and it does an OK job (not great) with HTML mail. I wish it would just drop the stupid GTK HTML widget and go with some form of embedded Mozilla/gecko.

    I do suspect that evolution is significant enough choice among people who really care about email that it matters.

    Also, mutt does a really poor job with HTML mail, but that probably falls into your power-nerd category.

  31. franklinmint says:

    While your client percentages are roughly correct in my experience, many ISPs (including AOL, I think) will let you turn off HTML email as a sort of anti-spam feature (your kids will not see throbbing body parts).

    Most marketing email is sent as Mime-Multipart. You can get a rough guess of your list after your first spamblast by giving different links in the two versions.

  32. jakenelson says:

    Pardon the week-late response, but...

    "Besides that, even if a mail program had a switch that let you say "convert HTML to plain-text before showing it to me" (and I can't imagine that feature existing except in a tty program) it would also be possible to turn that switch off when you need to."

    Outlook Express has had such a switch for about a year now.
    (Tools > Options > Read > Read all messages in plain text)
    It works remarkably well.